| 摘要 |
PURPOSE:To prevent the intervention of impurities and to obtain a refined and clean billet, by making the granular refining agent packed in a hollow molding for closing a nozzle hole dispersible into the molten metal which flows downward in the stage of charging the same. CONSTITUTION:Refractory particles of silica sand, alumina, or the like coated with, for example, a thermosetting resin are formed to a hollow molding 1 conforming to a nozzle hole 12. A granular refining agent 2 is packed in the molding 1 and is loaded into a sliding nozzle 10. When molten metal 16 is charged, the molding 1 is broken and the agent 2 is dispersed into the molten metal 16 which flows downward. The intervention of impurities is thus prevented, and the refining effect of the molten metal 16 is obtd., whereby a clean billet is yielded. |
